Washer and spin drier tub assembly



April 7, 1959 T. R. SMITH WASHER AND SPIN DRIER TUB ASSEMBLY '2 Sheets-Sheet 1 Filed Sept. 25, 1954.

April 7, 1959 T. R. SMITH 2,880,873

' WASHER AND SPIN DRIER TUB ASSEMBLY Filed sept. 25, 1954 v 2 sheets-sheet 2 United States Patent O WASHER AND SPIN DRIER TUB ASSEMBLY Thomas R. Smith, Newton, Iowa, assignor to The Maytag Company, Newton, Iowa, a corporation of Delaware Application September 23, 1954, Serial No. 457,901

17 Claims. (Cl. 210-147) This invention relates to washing machines for fabrics and more particularly to washing machines utilizlng a double tub assembly rotatable on a vertical axis for the centrifugal extraction of fluids from fabrics within the tub. Specifically, this invention relates to an improvement of that type double tub construction to permit sand and heavy sediment separated from the fabrics during the agitation period prior to the centrifugal extraction period to be rapidly removed from within the double tub assembly during the extraction process.

This invention constitutes an improvement over the type of double tub construction disclosed in my Patent No. 2,645,108 and assigned to the same assignee as the instant application. In that disclosure soiled fabrics were placed within an inner basket having a perforate cylindrical sidewall and a perforate bottom wall in spaced relationship to an outer imperforate tub which was fastened to the basket and retained the washing fluid during the agitation and rinse periods. In the spin periods following the agitation and rinse periods, the agitator unit and double tub assembly Were spun as an integral unit to extract all liquids through the walls of the perforate basket and over the top of the vertical sidewall of the outer 'imperforate tub without passing through the fabrics and thereby redepositing the separated sand, dirt. and other sediment on the fabrics during the centrifugal extraction process.

This double tub assembly formed from the perforate inner basket nested in spaced relationship with an outer imperforate tub provided a tub assembly having more desirable features than were obtained by the use of the single imperforate tub alone. First, the perforate basket served as a container for the fabrics while separating the heavier dirt and sediment from the fabrics through its perforate bottom. Furthermore, the basket provided a more rapid and thorough fluid extraction through its.l perforate periphery for a given speed than could be accomplished by the use of a single imperforate tub. Finally, the use of the basket in conjunction with the spaced fluid retaining outer imperforate tub provided arr annular upstanding fluid escape channel between the basketA and outer tub so as to prevent recontaminatiorr of thefabrics by the centrifugally extracted fluids as theyr passed from the tub assembly.

However, due to the high speed of rotation necessary to achieve an eflicient fluid extraction from the fabrics,l some sand and sediment separated from the fabrics and. deposited between the inner basket and outer tub during the agitation period was not flushed from the outer tuby because the vertical component of force of the water ris-- ing up the sidewall of the outer tub was insufficient toovercome the centrifugal force acting on the particles: of sand, etc., and resulted in these particles remaining' pressed against the sidewall of the outer tub during the: spin period. It was therefore not always possible to impart to the fluids being extracted a sufficient upwardly' directed velocity to overcome the effects of the centrif y ugal force and provide an adequate flushing or scouring Patented Apr. 7, 1959 ice of the space between the sidewalls of the inner basket and outer tub. An accumulation of sediment not capable of being removed over a series of cycles naturally pro duced the possible undesirable result of recontamination of the fabrics in subsequent washing operations.

It is therefore a principal object of this invention to provide an improved double tub assembly rotatable on its vertical axis whereby a sufficient vertical velocity may be imparted to the particles of sand and heavy sediment within the double tub assembly to overcome the action of the centrifugal force tending to prevent adequate scouring of these particles from within the space between the inner perforate basket and outer imperforate tub forming a part of the double tub assembly.

It is a further object to provide an improved double tub assembly capable of removing sand and other sediment from the space between the inner basket and outer imperforate tub during the first portion of the centrifugal extraction period while efficiently extracting residual fluids through the cylindrical wall of the perforate basket during the latter part of the centrifugal extraction process.

It is a further object of this invention to provide an improved double tub assembly which will permit an eilicient sediment removal from within the double tub assembly at the beginning of the centrifugal extraction period without impairing the efficiency of the fluid extraction from the fabrics at higher centrifugal speeds at the latter portion of the centrifugal extraction period.

Specifically, it is an object of this invention to provide a double tub assembly having an outer imperforate tub and a foraminous inner basket fastened in spaced relationship to the tub and having its perforate cylindrical periphery covered at lower centrifugal speeds by a resilient membrane in order to force water and sediment downwardly through the perforate bottom of the basket and then upwardly between the outer tub and resilient membrane in a rapid scouring action before higher centrifugal speeds expand the resilient membrane to uncover the cylindrical perforate periphery and remove the remaining residual fluids through the perforate cylindrical periphery of the basket at the end of the centrifugal extraction operation.

It is still a further object of this invention to provide an improved double tub assembly which is economical as well as efllcient in the removal of both fluids and heavy sediment from within the tub during the fluid extraction process.

Other objects and advantages of this invention will be apparent after reference is made to the following specification as illustrated in the accompanying drawings,

in which:

`Figure 1 is a vertical fragmentary view, partially in section, of a double tub assembly incorporating the principles of my invention.

Figure 2 is a cross sectional View taken on line 2-2 of Figure 1. v

Figure 3 is a partial vertical cross section taken on line 3-3 of Figure 2 of a double tub assembly (without an agitator) through one of the two sump areas showing the position assumed by the resilient membrane between the inner basket and outer tub when the double tub assembly is rotated at higher centrifugal speeds during the latter part of the extraction process following the removal of sand or other sediment from the tub.

Referring now in more detail to the drawing of a combined washing and centrifugal liquid extraction machine embodying a rotatable tub of double wall construction made in accordance with my present invention, there is shown in Figure 1 an outer imperforate tub 10, an innerV basket 11 and an agitator unit 12. Outer perforate tub 10 is provided with an upwardly directed and slightly outwardly sloping sidewall 13 having an upper terminal edge 14 disposed above the normal liquid level (.line A, Figure l) maintained in the tub for washing operations. Lower wall 15 having an inner terminal portion 16 overlapping flange 17 of gear housing 18 is fastened to flange 17 lby means of bolts 19 to form an integral unit with tub 10. Gasket 20 provides a liquid seal between tub and the top of gear housing 18 forming 1the central bottom portion of the double tub assembly. Outer Vconcentric shaft 23, shown integrally formed with gear housing 18,I is rotatably mounted and supports tub 10 on a thrust bearing (not shown) at the lower end of that shaft. Inner shaft 24 driven from an external power unit .(not shown) drives through the agitator .gear mechanism within gear housing 18 to oscillate agitator 12 in a conventional manner.

Inner basket 11, having walls 26 and 27 in substantially parallel spaced relationship to walls 13 and 15 respectively, is securely fastened to tub 10 by means of bolts 28 carrying nuts 30 and extending through cylindrical wall 26 and spacer members 29 to maintain the proper spacing between the walls of tub 10 and basket 11. Inner depending edge portion 31 of bottom Wall 27 is seated against an annular gasket 32 of a generally .U-shaped cross section in lrecess 33 of lower wall 15. This arrangement aids in maintaining the spaced relationship between the lower wall and bottom wall 27 while preventing pins, buttons, etc. from slipping past edge portion 31 into the sump areas between tub 10 and basket 11.

The upper portion 35 of basket 11 extends upwardly beyond edge 14 of tub 10 and inwardly towards an access opening generally defined by the rolled edge 36. This construction not only provides a means for preventing the discharge of Huid and fabrics over portion 35 during the centrifugal extraction operation but also provides a seat for balancing ring 38. Balancing ring 38, of the nature of that described in the above mentioned Patent No. 2,645,108, prevents the wobbling of the double tub assembly at speeds exceeding the critical speed of the tub assembly and forms no part of this invention.

Referring now particularly to the improvement made over the above mentioned Patent No. 2,645,108, it can be 4seen that cylindrical wall 26 is provided with a continuous band of holes 41 whereas bottom wall 27 is provided with a band of holes 42 which are partially discontinued over diametrically opposed sumps 43 formed in the lower wall 15. As may be apparent on the drawings, `the spaces between outer imperforate tub 10 and those perforate portions of inner basket 11 are large enough to permit sand and other sediment to pass into the space between tub 10 Iand basket 11 but not large enough to permit pins, hairpins or other objects of relatively long but restricted lateral measurements from entering into the space between tub 10 and basket. 11. No holes are provided in wall 27 directly over sumps 43 as the presencefof holes over these recessed sumps would aid in the passage of longer articles directly into these enlarged spaces between tub 10 and basket 11. The absence of holes directly over these sumps 43 also aids in the reduction of the turbulence of the particles which are ldeposited in sumps 43 after their passage through holes 42. However a presence of holes adjacent these sumps aids'in the ushing of these recesses during the extraction process while not causing substantial turbulence in the sumps during lthe agitation period.

Covering holes 41 to thereby form a substantially veri tical -channel 45 between tub 10 and basket 11 is a resilient membrane 46 stretched around cylindrical wall 26 and `maintained in position by spacer members 29 which pass through openings 47 formed in membrane 46. Skirtmembrane 46 is formed of a material such as rubber so as to permit its expansion away from wall 26 under the action yof centrifugal force at .a predetermined rotational speed. In thepreferred embodiment the mem- Abrane 46 is designed to open at speeds obtained when a greater portion of the fluids within the assembly have been extracted from the machine. The openings 47 are mismated with openings 41 and are of larger diameter than spacers 29 so as to permit membrane 46 to freely move away from basket 11 at higher speeds without permitting any leakage through holes 41 at the beginning of the extraction operation before skirt 46 has opened.

In operation of the double tub assembly described, the assembly is supported in a vertical position on outer concentric shaft 23 to expose the horizontal access opening defined by the rolled edge 36 to the operator of the unit. Fabrics are then placed within this opening and the tub assembly is lled with water and a suitable detergent to a predetermined level such as that indicated by the line A (Figure 1). Tub 10, basket 11 and shaft 23 are restrained by a brake mechanism (not shown) during the agitation periods when agitator 12, driven by inner shaft 24 and the oscillating drive mechanism (not shown) within gear housing 1S, agitates the fabrics .in the washing uid to separate an existing sand and sediment from the fabrics. Sand and heavier sediment settling to the bottom wall 27 pass through holes 42 and works their way along bottom wall 15 into the sump areas 43 where they remain during the remainder of the agitation period.

At the termination of the agitation period, the movement of agitator 12 with respect to tub 10 and basket 11 is terminated, and the ybrake restraining the tub 10 from rotation is released permitting tub 10, basket 11 and agitator 12 to be spun as an integral unit through outer concentric shaft 23.

The rotating tub assembly develops a fiuid pressure head within basket 11 proportional to the radius and speed of the rotating assembly which causes the water within the basket 11 to flatten against the inner surface of wall 26. The water level immediately surrounding agitator 12 quickly drops causing a surface of the water to form a rough paraboloid as the water rises toward portion 35 of basket 11. An increasing pressure differential is created between the rising pressure head Within the spinning basket and the pressure exerted on the water in the upper portion of channel 45. This pressure differential forces water downwardly through holes 42,

past sumps 43 and upwardly into narrow channel 45 before passing over terminal edge 14 at the exit of channel 45. The `quantity and velocity of water moving upwardly through narrow channel 45 rapidly results in a ilushing of the sediment particles from bottom wall 15 and sumps 43 as the upwardly directed forces of the water passing through channel 45 overcome the effects of the centrifugal forces tending to flatten the sarne particles against wall 13.

This scouring of the sediment particles from the bottom of the double tub assembly continues until most of the fluids within the assembly have been extracted and the assembly reaches the predetermined speed at which membrane opens and moves away from basket 11 to expose holes 41 in the manner illustrated in Figure 3. The uncovering of holes 41 in basket 11 permits the residual fluids attened against the inside of wall 26 to be extracted through holes 41 and over edge 14 to place the fabrics in a damp dry condition. It is during this latter portion of the extraction cycle when membrane 46 has moved outwardly against wall 13 that the liquid extraction process is similar to and retains the efficiency of the double tub assembly disclosed in my prior Patent No. 2,645,108. Upon the termination of the spin cycle, membrane 46 again contracts into its former position to cover holes 41 for the next agitation operation.

Thus it can be seen that I have provided a simple and economical double tub assembly capable of flushing separated sediment from within the assembly at lower speeds while retaining the advantages of a perforate centrifugal fluid extractor at higher rotational speeds. The construction disclosed is dependent solely upon the radius agssds'va and rotational speed of the assembly andan adequate amount of water for flushing purposes and therefore operates efficiently without control or attention of an 'operator during all spinning cycles of the washing operation.

I claim:

1. A rotatable tub assembly comprising' an outer tub, an inner tub, first and second means each associated with said inner tub and providing communication between said inner and outer tubs, a sump adjacent said second means, and speed responsive means controlling the communication provided by said first means.

2,. A rotatable double tub assembly for washing machines comprising an outer tub, an inner tub, first and second openings in said inner tub each providing communication between said inner and outer tubs, a sump adjacent said second openings, and resilient speed responsive means covering said first openings and regulating communication between said inner and outer tubs through said first openings.

3. A double tub assembly comprising an outer tub, an inner tub in spaced relation to said outer tub, shaft means'for'rotating said vinner tub, a first perforate portion `in said inner tub, centrifugally operable valve means closing said first perforate portion, and a second perforate portion in said inner tub providing communication between said tubs independent of the rotational speed of said inner tub.

4. A double tub assembly comprising an outer tub, an inner tub fastened in spaced relation to said outer tub, shaft means for rotating said tubs in unison, a first perforate portion in said inner tub, a resilient band between said tubs covering said first portion and responsive to the rotational speed of said double tub assembly, a second perforate portion in said tub providing communication between said tubs independent of the rotational speed of said double tub assembly, and a sediment reservoir associated with said outer tub adjacent said second perforate portion.

5. A double tub assembly comprising an outer tub, an inner tub fastened in spaced relation to said outer tub, said inner tub having a perforate periphery and a perforate base portion, shaft means for rotating said tubs in unison at high and low speeds, a sump recess in said outer tu-b adjacent said base portion, and speed responsive means covering said perforate periphery at said low speeds and uncovering said perforate periphery at said high speeds.

6. A rotatable tub assembly having an inner perforate wall portion, an outer imperforate wall portion, centrifugally responsive means normally covering said perforate wall portion and forming a channel between said imperforate wall portion and said centrifugally responsive means, and means adjacent the bottom of said channel providing communication from within said tub assembly to said channel.`

7. A rotatable tub assembly having inner perforate side and bottom wall portions, an outer imperforate side wall portion, valve means normally covering said perforate sidewall portion and forming a channel between said imperforate sidewall portion and said valve means, and sump means communicating with said perforate bottom portion and said channel.

8. A rotatable tub assembly having inner perforate side and bottom wall portions, an outer imperforate wall portion, shaft means for rotating said assembly through a range of high and low speeds, a flexible band covering said perforate sidewall portion at said low speeds and forming a channel between said imperforate sidewall portion and said flexible band, and sump means communicating with said perforate bottom wall portion and said channel.

9. A tub assembly adapted to retain fluid and fabrics during a fluid extraction operation comprising, an imperforate walled member defining a containerfor the retention of said fluid, a wall positioned inside said container and spaced therefrom to define with said container a channel for the discharge of fluid from said tu-b assembly during said extraction operation, said wall including a plurality of openings leading into said channel, speed responsive means sealing said openings and precluding communication through said wall by way of said openings, means providing a channel intake spaced from said openings, means for rotating said wall from rest to a final centrifuging speed to develop a fluid pressure head for forcing said fluid through said intake and into said channel to scour said channel and said container free of sediment separated from fabrics placed within said tub assembly, said speed responsive means unsealing said openings prior to the acceleration of said wall to said final centrifuging speed to centrifuge fluid from said fabrics directly into said channel by way ofsaid openings.

l0. A revoluble tub assembly adapted to retain fluid and fabrics during a fluid extraction operation comprising, an imperforate walled member defining a container for the retention of said fluid, a wall positioned inside said container and spaced therefrom to define with said container a channel for the discharge of fluid from said tub assembly during said extractonoperation, said wall including a plurality of openings leading into said channel, centrifugally responsive means positioned in said channel and sealing said openings to preclude communication through said wall Iby way of said openings, means in said wall providing an intake into said channel spaced from said openings, means for rotating said wall from rest to a final centrifuging speed to develop a fluid pressure head for forcing said fluid through said intake and into said channel to scour said channel and said container free of sediment separated from fabrics placed within said tub assembly, said centrifugally responsive means opening said openings prior to the acceleration of said wall to said final centrifuging speed to centrifuge fluid from said fabrics directly into said channel by Way of said openings.

11. A revoluble tub assembly adapted to retain fluid and fabrics during the fluid extraction operation comprising, means defining a container for the retention of said fluid, a wall positioned inside said container and spaced therefrom to define an annular channel for the discharge of fluid from said tub assembly during said extraction operation, said wall including a plurality of openings, a resilient band positioned Within said channel and encompassing said wall to preclude communication through said wall by way of said openings, means spaced from said openings dening a channel intake for the discharge of fluid from said tub assembly, means for rotating said wall and said container in unison from rest to a nal centrifuging speed to develop a fluid pressure head to force said fluid through said intake and into said channel to scour said channel and said container free of sediment separated from fabrics placed within said tub assembly, said resilient band expanding away from said openings prior to the acceleration of said wall to said final centrifuging speed of to centrifuge fluid from said fabrics directly into said channel by way of said openings.

12. The invention of claim l1 in which said container includes a sump positioned adjacent said intake to retain accumulated sediment separated from said fabrics.

13. A revoluble tub assembly adapted to retain fluid and fabrics during a fluid extraction operation comprising, an upstanding imperforate container for retaining said fluid, a walled member fastened to said container and including an upstanding perforate wall portion spaced from said container and cooperating therewith to define a channel for the discharge of fluid from said tub assembly during said extraction operation, said walled member further including a perforate extension positioned within said container adjacent the bottom of said contailler and extending inwardly of said container to provide an intake into said channel, a resilient band encompassing ,Said perforate wall portion and precluding communication through said Wall portion, means for rotating said container and said Walled member from rest to a final centrfuging speed to develop a iluid pressure head for forcing said Huid downwardly through said intake and into said channel to scour the said container free of Sediment separated from fabrics placed within said tub assembly, said resilient band expanding and uncovering said perforate wall portion prior to the ac-celeration of Said container and said walled member to said nal centrifuging speed to centrifuge iluid from said fabrics directly into said channel by way of said perforate wall portion.

14. The invention of claim 13 in which said container and said upstanding perforate wall portion are substantially cylindrical in configuration and cooperate with each other to define an annular channel receiving saidr resilientband.

15. The invention of claim 14 in which said resilient band is endless and is stretched around the periphery of said perforate. wall portion to bias said resilient band against said wall portion.

16. A tub assembly for the centrifugal extraction of ui'ds comprising, a container for said fluids, said container including an imperforate sidewall and an imperforate bottom, an inner perforate sidewall fastened within said container and spaced from said imperforate side Wall, said inner perforate sidewall provided with an inwardly directed perforate bottom extension which covers said container bottom and is spaced therefrom, drive means for rotating said container, and a resilient band covering the periphery of said perforate sidewall and cooperating with said mperforate sidewall to form an up standing 4channel communicating with the interior of said container for regulating fluid flow through said perforate sidewall inresponse to the rotational speed imparted to said container by said dri-ve means.

17. The invention set forth in claim 16 further comprising at least one sump pocket formed in said container bottom immediately adjacent to the lowermost end of lsaid upstanding channel formed by said resilient band and said imperforate sidewall.

References Cited in the le of this patent UNITED STATES PATENTS 1,751,982 Dunham Mar. 25, 1930r 2,630,816 Smith Mar.v 10, 1953 2,645,109 Smith July 14, 1953 2,683,364 Kirby July 13, 1954 2,683,535 Smith July 13, 1954 

